Cataract extraction is the most common ophthalmic surgical procedure performed in the United States. Extracapsular cataract extraction involves cutting a portion of the anterior capsule (anterior capsulorhexis) followed by removal of the nucleus. Alternatively, a probe may be inserted through the anterior capsule and ultrasonically vibrated, transforming lens material into an emulsion is then irrigated and aspirated from the capsular bag (phacoemulsification). After removal of the natural lens, images no longer focus on the retina and a replacement lens must be provided for clear vision. Replacement lenses can be glasses, contact lenses or intraocular lenses. Of these, intraocular lenses give the greatest convenience and undistorted vision. In ten percent or greater of extracapsular extractions, the posterior capsule is ruptured during aspiration of the cortex, making it impossible to use regular posterior lens implantation in the bag. Prior to the invention, anterior chamber intraocular lenses have been used as standbys since commercially available capsular lenses would enlarge the tear. Such anterior chamber lenses can cause complications such as damage to the vascularly rich iris of the eye.
U.S. Pat. No. 4,750,904, incorporated herein by reference, explains some complications arising from anterior chamber implants. This patent discloses a posterior chamber lens sutured directly to the iris for use after an intraocular lens extraction has left no capsular platform to hold a lens.
The present invention is directed toward the use of the ciliary sulcus and the anterior capsular membrane to retain and support a lens in the natural position.